Educational toys, talking games and similar devices often employ synthesized sound effects and character voices to communication with a user. Such devices have traditionally used linear predictive coding (LPC) techniques to reproduce speech. Linear predictive coding, however, is generally not able to reproduce sophisticated sounds or high quality speech.
More recently, code-excited linear prediction (CELP) systems have been used to provide synthesized speech. CELP systems generally use both fixed and adaptive excitation signals which are combined and synthesized with linear predictive coding (LPC) coefficients. CELP systems are often resource intensive and generally require 16 bit precision. Accordingly, CELP systems are not readily adaptable to many existing speech synthesizer chips.